This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A089710 #8 Dec 05 2013 19:56:36 %S A089710 3,1,6,9,4,20,13,29,19,2,7,18,12,41,36,30,72,25,27,8,28,42,47,114,85, %T A089710 38,16,117,177,24,11,66,34,53,37,264,48,126,96,87,39,261,99,65,124, %U A089710 419,21,147,55,321,240,62,40,69,92,60,49,287,289,393,227,745,84,149,58,54,141 %N A089710 a(1) = 3. For n > 1, a(n) is the least unused number such that the concatenation a(n)a(n-1)...a(2)a(1) is prime. %C A089710 Is this a rearrangement of the natural numbers? %e A089710 3, 13, 613, 9613, 49613, 2049613, ... etc. are primes. %Y A089710 Cf. A089711. %K A089710 base,nonn %O A089710 1,1 %A A089710 _Amarnath Murthy_, Nov 17 2003 %E A089710 More terms from _Ray Chandler_, Nov 21 2003 %E A089710 Edited by _Charles R Greathouse IV_, Apr 29 2010